We discuss the QCD sum rule calculation of the heavy-quark effective theory parameters, $��_E$ and $��_H$, which correspond to matrix elements representing quark-gluon three-body components in the $B$-meson wavefunction. We derive the sum rules for $��_{E,H}$ calculating the new higher-order QCD corrections, i.e., the order $��_s$ radiative corrections to the Wilson coefficients associated with the dimension-5 quark-gluon mixed condensates, and the power corrections due to the dimension-6 vacuum condensates. We find that the new radiative corrections significantly improve the stability of the corresponding Borel sum rules and lead to the reduction of the values of $��_{E,H}$. We also discuss the renormalization-group improvement for the sum rules and present update on the values of $��_{E,H}$.

28 pages, 20 figures, version to appear in Nuclear Physics B